Mammalian sperm antigens will be investigated with respect to: 1) origin during spermatogenesis and from the accessory glands (sperm coating antigens); 2) subcellular localization and compartmentalization in the mature sperm; 3) role in reproduction; 4) chemical characterization and especially 5) possible use as agents for fertility control through immunological means. Objectives 1 and 2 will employ antibody labeling techniques in conjunction with fluorescence and especially electron microscopy; objective 3 will continue current experiments exploring for and specifying roles for sperm antigens in reproduction using antibodies and antibody fragments (Fab, Fab1 sub 2, Fab1) as inhibitors of sperm function; objective 4 will utilize techniques in the literature or development of methods for special situations with the following examples of available instrumentation: gradient preparative ultracentrifugation, column chromatography, acrylamide gel electrophoresis (both analytical and preparative); in objective 5 antigens of significance in reproduction (e.g. inhibited by antibody) will be examined for isoantigenicity in both the male and female for production of immunological infertility in both sexes. Guinea-pigs will be standard material in the spermatogenesis studies because of the background of information and experience in the lab. Rabbits will be standard material for sperm function and reproduction studies. When significant results are obtained on guinea- pigs or rabbits, the experiments will be extended to monkeys at the Delta Regional Primate Center and finally to clinical material when available from the School of Medicine, University of Miami.